Elementary text-book of zoology (1884) Elementary text-book of zoology elementarytextbo0101clau Year: 1884 NOCTILTTCA. 197 of the sea, and possesses a peach-shaped body which is surrounded by a cuticular envelope, and bears a tentacle-like appendage. A furrow- like invagination is situate at the base of this appendage, at one end of which is the mouth close to a tooth-like prominence and a slender vibratile flagellum. The soft body consists of a central mass of contractile protoplasm, connected by fine and anastomosing threads with a layer of the same substance which lines the cuticular envel
Elementary text-book of zoology (1884) Elementary text-book of zoology elementarytextbo0101clau Year: 1884 NOCTILTTCA. 197 of the sea, and possesses a peach-shaped body which is surrounded by a cuticular envelope, and bears a tentacle-like appendage. A furrow- like invagination is situate at the base of this appendage, at one end of which is the mouth close to a tooth-like prominence and a slender vibratile flagellum. The soft body consists of a central mass of contractile protoplasm, connected by fine and anastomosing threads with a layer of the same substance which lines the cuticular envelope of the body. In the central protoplasm lies a clear body, the nucleus, and the spaces between the radiating processes, which exhibit the phenomena of granule currents, are filled with fluid. The contractile substance extends into the appendage, and there assumes a cross- striped appearance (fig. 136). FIG. 136.—Noctiluca miliaris (partly after CienkowsW). N, Nu- cleus, a, Single animal. I, conjugation of two individuals. c and d, swarm spores. The reproduction takes place by means of fission (Brightwell), pre- ceded by division of the nucleus ; or by spore formation (Zoospores). In the latter case, the flagellum is absorbed or thrown off, and the Noctiluca assumes a spheroidal After the disappearance of the nucleus, the sarcode contents accumulate on the inner side of one region of the cuticle, divide into from two to four masses which are not sharply separated from one another, and the cuticular envelope is thrust out into a corresponding number of protuberances. These Lmds increase and form numerous wart-like prominences, the future spores. They arise, therefore, at the expense of the protoplasmic contents of the disc, which is gradually exhausted in their for-
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